What is the net force acting on an object at t=2 with a given momentum equation?

[Nny]

Homework Statement

An objects momentum is given by the following equation p(t) = 4t³-6t+1. What net force is acting on the objects at t=2?

Homework Equations

P=m*v
F=Δp/Δt

The Attempt at a Solution

So, I was thinking if F=m*a I can change a and get F=m*(Δv/Δt) and knowing what I know about p, I change it to F=Δp/Δt

So then I was just solving the equation for t=2 and t=0 to get (21-1)/(2-0) = 10

Is that correct or am I totally thinking about this wrong?

 

[benoconnell22]

Remember that, F=dP/dt

 

[tiny-tim]

Hi Nny!

So, I was thinking if F=m*a I can change a and get F=m*(Δv/Δt) and knowing what I know about p, I change it to F=Δp/Δt

So then I was just solving the equation for t=2 and t=0 to get (21-1)/(2-0) = 10

as ben says, F = dp/dt, not ∆p/∆t,

so your basic idea is right, but your calculation is wrong

(btw, the proper version of good ol' Newton's second law is not F = ma, it's F = d(mv)dt … force = rate of change of momentum )